Didn't George Carlin say something like "The planet is fine, the people are fucked"?
Climate change is gonna cause a lot of needless suffering among human and non-human living things. Up to and including extinction events. But I think we'll end up reducing our own population faster than we can render the planet literally inhospitable to life.
Life, uh, finds a way.
But, yes, this is no excuse to do whatever we can to fight climate change.